1. Field of the Invention
The present invention relates to a rotation sensing device of a fan apparatus adapted to a chamber of a handler, and more particularly, to a rotation sensing device which can sense a rotational state of a fan apparatus for controlling the temperature of a chamber in a handler regardless of the ambient temperature of the fan apparatus.
2. Description of the Related Art
A handler is used for testing electrical properties of a semiconductor parts. The handler is constructed in such a manner that an elevator/tray transfer, an X-Y robot, an exchanger, and a chamber are installed on a base frame. The tray on which semiconductor parts are loaded are moved to the elevator/tray transfer, and then the semiconductor parts loaded on the tray are moved to an aligner by the X-Y robot. The semiconductor parts moved to the aligner are displaced to a test tray by the exchanger and thereafter are moved to the chamber to be tested.
The chamber includes a preheater, a test site and a defroster. The preheater preheats the semiconductor parts loaded on the test tray, and the test site tests the electric properties of the semiconductor parts loaded on the test tray which have passed through the preheater in a high temperature and low temperature state. When the testing of the semiconductor parts is finished at the test site, the tested test tray is moved to the defroster and then is discharged after the defroster makes the temperature of the semiconductor parts an ambient temperature.
To test the electric properties of the semiconductor parts at the chamber, as described above, a fan apparatus is provided inside the chamber in order to control the internal temperature of the chamber. The construction of the fan apparatus will now be described with reference to FIG. 1.
FIG. 1 is a perspective view of a fan apparatus adapted to a chamber of a handler according to the conventional art. As illustrated therein, the fan apparatus includes a rotary motor 1, a coupling 2, a shaft 3, a case 4 and a plurality of bearing housings 5.
The rotary motor 1 is installed outside the chamber (not shown), and the shaft 3 is connected to a rotary central axis la of the rotary motor 1 installed inside the chamber by using the coupling 2. The shaft 3 is installed inside the case 4, and grease is filled inside the case 4 in a state that the bearing housing is installed at both ends of the case 4.
To sense whether the fan apparatus used for control the internal temperature of the chamber by rotating the shaft 3 is rotated or not, as shown in FIG. 1, a thermocouple 8 is used at the cylindrical surface of the fan apparatus according to the conventional art. The thermocouple 8 provides a temperature source to a main controller 100 by sensing the internal temperature of the chamber and transferring it to the main controller 100 of the handler, so that the main controller 100 can check the rotational state of the fan apparatus. Thus, the main controller 100 can control the internal temperature of the chamber by using the temperature source provided from the thermocouple 8, and can sense whether the fan apparatus is rotated or not by using the temperature source in a case that the fan apparatus is not rotated due to the breakage of the coupling 2 and the like of the fan apparatus.
In case of sensing whether the fan apparatus is rotate or not by using the thermocouple according to the conventional art, it is not discriminated whether the fan apparatus is normally rotated or not if the thermo couple is wrongly operated or is not operated, thus making it impossible to control the internal temperature of the chamber.
It is, therefore, an object of the present invention to provide a rotation sensing device which can sense whether the fan apparatus for controlling the temperature of the chamber of a handler is rotated or not by sensing a rotation state of a sensor dog installed to a shaft of the fan.
It is another object of the present invention to sense directly whether the fan apparatus is rotated or not regardless of the ambient temperature of the fan apparatus by sensing the rotation state of the sensor dog installed to the shaft of the fan.
To achieve the above object, there is provided a rotation sensing device of a fan apparatus adapted to a chamber of a handler comprising: a sensor dog being installed at the outer circumferential surface of a shaft installed inside a case and being configured to be spread a predetermined length larger than the diameter of the stop state when a centrifugal force is generated by the rotation of the shaft; an optical sensor receiving light reflected from the surface of the sensor dog and producing a sensing signal of the light if the sensor dog is spread the predetermined length by scanning the light to the sensor dog; and a main controller judging that the fan apparatus is rotated upon receipt of the sensing signal of the light from the optical sensor.